package com.atguigu.yygh.user.utils;

import javax.servlet.http.HttpServletRequest;
import java.net.InetAddress;
import java.net.UnknownHostException;

/**
 * @author ybl
 * @version 1.9
 * @date 2021/5/20 15:25
 */
public class IpUtil {
  private static final String UNKNOWN = "unknown";
  private static final String LOCALHOST = "127.0.0.1";
  private static final String SEPARATOR = ",";

  public static String getIpAddr(HttpServletRequest request) {
    System.out.println(request);
    String ipAddress;
    try {
      ipAddress = request.getHeader("x-forwarded-for");
      if (ipAddress == null || ipAddress.length() == 0 || UNKNOWN.equalsIgnoreCase(ipAddress)) {
        ipAddress = request.getHeader("Proxy-Client-IP");
      }
      if (ipAddress == null || ipAddress.length() == 0 || UNKNOWN.equalsIgnoreCase(ipAddress)) {
        ipAddress = request.getHeader("WL-Proxy-Client-IP");
      }
      if (ipAddress == null || ipAddress.length() == 0 || UNKNOWN.equalsIgnoreCase(ipAddress)) {
        ipAddress = request.getRemoteAddr();
        if (LOCALHOST.equals(ipAddress)) {
          InetAddress inet = null;
          try {
            inet = InetAddress.getLocalHost();
          } catch (UnknownHostException e) {
            e.printStackTrace();
          }
          ipAddress = inet.getHostAddress();
        }
      }
      // 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
      // "***.***.***.***".length()
      if (ipAddress != null && ipAddress.length() >15) {
        if (ipAddress.indexOf(SEPARATOR) >0) {
          ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
        }
      }
    } catch (Exception e) {
      ipAddress = "";
    }
    return ipAddress;
  }
}

